Electric wire

ABSTRACT

An electric wire, in which a color of an outer surface of the electric wire is securely prevented from coming off, is provided. The electric wire ( 1 ) includes a core wire ( 4 ), coating ( 5 ), mark ( 23 ) and coating layer ( 6 ). The coating ( 5 ) coats the core wire ( 4 ). The mark ( 23 ) is formed on an outer surface ( 5   a ) of the coating ( 5 ). A coloring agent is allowed to adhere to the outer surface ( 5   a ), thereby forming the mark ( 23 ). The coating layer ( 6 ) is formed on the mark ( 23 ) and the outer surface ( 5   a ). The coating layer ( 6 ) consists of PVA. A thickness of the coating layer ( 6 ) consisting of PVA may be from 0.02 mm to 0.22 mm.

TECHNICAL FIELD

The present invention relates to an electric wire including anelectrically conductive core wire, an insulating coating which coats thecore wire, a mark formed on an outer surface of the coating, and acoating layer which coats the mark.

BACKGROUND ART

Various electronic devices are mounted on a motor vehicle as a mobileunit. Therefore, the motor vehicle is provided with a wiring harness fortransmitting power from a power source and control signals from acomputer to the electronic devices. The wiring harness includes aplurality of electric wires and connectors attached to an end of thewires.

The wire includes an electrically conductive core wire and a coatingmade of insulating synthetic resin, which coats the core wire. The wireis a so-called coated wire. A connector includes an electricallyconductive terminal fitting and an electrically insulating connectorhousing. The terminal fitting is attached to an end of the wire andelectrically connected to the core wire of the wire. The connectorhousing is formed in a box-shape and receives the terminal fittingtherein.

When the wiring harness is assembled, first the wire is cut into aspecific length and then the terminal fitting is attached to an end ofthe wire. A wire is connected to another wire according to the need.Afterward, the terminal fitting is inserted into the connector housing,thereby assembling the wiring harness.

The wire of the wiring harness must be distinguished in terms of thesize of the core wire, the material of the coating (concerning withalteration in the materials depending upon heat-resisting property), anda purpose of use. The purpose of use means, for example, an air bag,antilock brake system (ABS), control signal such as speed data, andsystem in a motor vehicle in which the wire is used, such as a powertransmission system.

So far, in order to distinguish the purpose of use (or system) asdescribed above, for example, an outer surface of the electric wire ofthe wiring harness is formed to have a stripe pattern with two differentcolors. In this case, when the coating is formed by extruding syntheticresin onto the periphery of the core wire so as to coat the core wire,first a coloring agent having a desired color is mixed into thesynthetic resin that constitutes the coating. Then, another coloringagent having a color different from that of said desired color isapplied on the synthetic resin (i.e. on a part of the outer surface ofthe coating). Thus, the part of the outer surface of the coating iscolored so as to color the electric wire in a stripe pattern.

Generally, a motor vehicle is used for a long period of time fromseveral years to more than ten years. Further, a motor vehicle may beused in various regions such as very cold regions or very hot regions.Therefore, if the electric wire used in a motor vehicle is colored in astripe pattern, the coloring agent, particularly the coloring agentwhich is applied later, tends to come off from the outer surface of theelectric wire as time passes.

Further, since the motor vehicle is used for a long period of time asdescribed above, it happens that a new electronic instrument is addedthereinto during use. Therefore, if the coloring agent comes off fromthe outer surface of the electric wire, it becomes difficult todistinguish the electric wires from one another, resulting in that itbecomes difficult to electrically connect the additional electricinstrument to a desired electric wire. That is, it is demanded that thecolor of the outer surface of the electric wire used in a motor vehicledoes not come off in severe circumstances for a long period of time.

It is therefore an objective of the present invention to provide anelectric wire, in which a color of the outer surface of the electricwire is securely prevented from coming off.

DISCLOSURE OF THE INVENTION

In order to solve the above problem and to attain the above objective,the present invention defined in claim 1 is an electric wire including:

an electrically conductive core wire;

a coating consisting of synthetic resin for coating the core wire;

a mark formed on a part of an outer surface of the coating by allowing acoloring agent to adhere to the part; and

a coating layer formed on the mark and the outer surface of the coating,the coating layer coating the mark,

wherein the coating layer consists of polyvinylalcohol.

The present invention defined in claim 2 is the electric wire accordingto claim 1, wherein a thickness of the coating layer is from 0.02 mm to0.22 mm.

The present invention defined in claim 3 is the electric wire accordingto claim 1, wherein a thickness of the coating layer is from 0.023 mm to0.22 mm.

The present invention defined in claim 4 is an electric wire including:

an electrically conductive core wire;

a coating consisting of synthetic resin for coating the core wire;

a mark formed on a part of an outer surface of the coating by allowing acoloring agent to adhere to the part; and

a coating layer formed on the mark and the outer surface of the coating,the coating layer coating the mark,

wherein the coating layer consists of ethylene-vinylalcohol copolymer.

The present invention defined in claim 5 is the electric wire accordingto claim 4, wherein a thickness of the coating layer is from 0.03 mm to0.175 mm.

The present invention defined in claim 6 is the electric wire accordingto claim 4, wherein a thickness of the coating layer is from 0.1 mm to0.175 mm.

In the electric wire of the present invention as defined in claim 1, thecoating layer is formed on the mark formed on the outer surface of theelectric wire. The coating layer consists of polyvinylalcohol.

In this specification, the coloring agent means a liquid substance, inwhich a coloring material (organic substance for use in industry) isdissolved and dispersed in a solvent except water. The organic substancedescribed above is a dye or a pigment (most of them being organicsubstances and synthetic substances). Sometimes, a dye is used as apigment and a pigment is used as a dye. As an example, the coloringagent may be a coloring liquid or coating material.

The coloring liquid is a liquid, in which a dye is dissolved ordispersed in a solvent. The coating material is a material, in which apigment is dispersed in a liquid dispersion. When the outer surface ofthe coating is colored with a coloring liquid, the dye permeates intothe coating. When the outer surface of the coating is colored with acoating material, the pigment adheres to the outer surface withoutpermeating into the coating. In the specification, “to color the outersurface of the coating” means to dye the whole or a part of the outersurface of the wire with a dye or, alternatively, to coat the whole or apart of the outer surface of the wire with a pigment.

Preferably, the solvent and liquid dispersion have an affinity to thesynthetic resin that constitutes the coating in order to allow the dyeto securely permeate into the coating or to allow the pigment tosecurely adhere to the outer surface of the coating. The dye of thecoloring liquid and the pigment of the coating material are oil-soluble.That is, the dye of the coloring liquid does not dissolve or disperse inwater. The pigment of the coating material does not dissolve in water.

Since the dye of the coloring liquid and the pigment of the coatingmaterial are oil-soluble, the coloring agent hardly passes through thecoating layer consisting of water-soluble polyvinylalcohol. Therefore,the coating layer prevents' the coloring agent, which forms the mark,from coming off from the outer surface of the electric wire.

In the electric wire of the present invention as defined in claim 2, athickness of the coating layer is from 0.02 mm to 0.22 mm. Therefore,the coating layer securely prevents the coloring agent, which forms themark, from coming off from the outer surface of the electric wire.

In the electric wire of the present invention as defined in claim 3, athickness of the coating layer is from 0.023 mm to 0.22 mm. Therefore,the coating layer more securely prevents the coloring agent, which formsthe mark, from coming off from the outer surface of the electric wire.

In the electric wire of the present invention as defined in claim 4, thecoating layer is formed on the mark formed on the outer surface of theelectric wire. The coating layer consists of ethylene-vinylalcoholcopolymer. Since the dye of the coloring liquid and the pigment of thecoating material are oil-soluble, the coloring agent hardly passesthrough the coating layer consisting of water-solubleethylene-vinylalcohol. Therefore, the coating layer prevents thecoloring agent, which forms the mark, from coming off from the outersurface of the electric wire.

In the electric wire of the present invention as defined in claim 5, athickness of the coating layer is from 0.03 mm to 0.175 mm. Therefore,the coating layer securely prevents the coloring agent, which forms themark, from coming off from the outer surface of the electric wire.

In the electric wire of the present invention as defined in claim 6, athickness of the coating layer is from 0.1 mm to 0.175 mm. Therefore,the coating layer more securely prevents the coloring agent, which formsthe mark, from coming off from the outer surface of the electric wire.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a structure of an electricwire-cutting device for obtaining an electric wire according to apreferred embodiment of the present invention;

FIG. 2 is a view illustrating a structure of an electric wire-coatingdevice mounted on the electric wire-cutting device shown in FIG. 1;

FIG. 3 is a view illustrating a structure of a control device of theelectric wire-coating device shown in FIG. 2;

FIG. 4 is a view illustrating a state when a spouting unit of theelectric wire-coating device shown in FIG. 2 is in action;

FIG. 5 is a perspective view of an electric wire according to apreferred embodiment of the present invention;

FIG. 6 is a cross sectional view taken along VI-VI line in FIG. 5;

FIG. 7 is a plan view of the electric wire shown in FIG. 5;

FIG. 8 is a cross sectional view taken along VIII-VIII line in FIG. 7;

FIG. 9 is a graph illustrating a change in a degree of color-coming-offof a coloring agent when a thickness of a coating layer of the electricwire shown in FIG. 5 is changed;

FIG. 10A is a schematic view illustrating a condition when the degree ofcolor-coming-off shown in FIG. 9 is measured; and

FIG. 10B is a plan views illustrating a sheet material used in FIG. 10Aand a comparative sheet material.

BEST MODE FOR CARRING OUT THE INVENTION

In the following, an electric wire according to a preferred embodimentof the present invention will be explained with reference to FIGS. 1-10.

An electric wire 1 constitutes a wiring harness to be mounted on a motorvehicle or the like as a mobile unit. As shown in FIG. 5 and so on, thewire 1 includes an electrically conductive core wire 4 and anelectrically insulating coating 5. A plurality of element wires arebundled up to form the core wire 4. Each element wire of the core wire 4is made of electrically conductive metal.

The core wire 4 may be constituted by a single element wire. The coating5 is made of synthetic resin such as polyvinyl chloride (PVC). Thecoating 5 coats the core wire 4. Therefore, the outer surface 5 a of thecoating 5 means an outer surface of the wire 1.

The outer surface 5 a of the coating 5 has a monochrome color P. Adesired coloring agent may be mixed with the synthetic resin of thecoating 5 so as to make the color of the outer surface 5 a of the wire 1be a monochrome color P, or alternatively, the monochrome color P may beset as the color of the synthetic resin itself without adding a coloringagent to the synthetic resin of the coating 5. That is, the wire 1 maynot be colored.

If a coloring agent is not mixed into the synthetic resin whichconstitutes the coating 5, that is, if the monochrome color P is a colorof the synthetic resin itself, the outer surface 5 a of the coating 5that is, the outer surface 5 a of the electric wire 1 is callednon-colored.

The electric wire 1 includes a plurality of marks 23 and a coating layer6. Each mark 23 is formed on a part of the outer surface 5 a of thecoating 5. As shown in FIG. 7, a shape of the mark 23 in its plan viewis round. A plurality of the marks 23 are arranged along thelongitudinal direction of the wire 1 in a predetermined pattern. Adistance D between centers of the two marks 23 adjacent to each otherand a size of each mark 23 are predetermined.

The mark 23 has a color B (shown with a parallel alternate long and twoshort dashes line in FIGS. 5 and 7). The color B is different from themonochrome color P. A coloring agent CH (explained later on) is allowedto adhere to a part of the outer surface 5 a of the wire 1, therebyforming the mark 23. The wires 1 are distinguishable from one another bychanging the colors B of the marks 23 in various manners. The color B isused to distinguish types of the wires of a wiring harness or systems inwhich the wires 1 are used.

As shown in FIGS. 5-8, the coating layer 6 is formed on the respectivemarks 23 so as to coat the marks 23. The coating layer 6 is formed onthe marks 23 and on the outer surface 5 a of the coating 5. The coatinglayer 6 prevents a dye or a pigment (explained later on), whichconstitutes the mark 23, from coming off from the outer surface 5 a.

The coating layer 6 consists of polyvinylalcohol (PVA). A thickness T(see FIG. 6) of the coating layer 6 may be from 0.02 mm to 0.22 mm.

A plurality of the electric wires 1 are bundled up with each other, thenconnectors or the like are attached to ends of the wires 1, therebyconstituting the wiring harness. Such connectors are coupled withconnectors of various electronic instruments in a motor vehicle or thelike, thereby the wiring harness transmits various signals and electricpower to the respective electronic instruments.

A long electric wire, on which the marks 23 and coating layer 6 are notformed, is cut by the electric wire-cutting device 2 shown in FIG. 1into a specific length, thereby the electric wire 1 is obtained. Acoating device 3 is mounted on the electric wire-cutting device 2. Thecoating device 3 forms the marks 23 and the coating layer 6 on the outersurface 5 a of the wire 1, which is cut into the specific length by theelectric wire-cutting device 2.

As shown in FIG. 1, the electric wire-cutting device 2 includes a body10, sizing mechanism 11 and cutting mechanism 12. The body 10 is formedin a box-shape. The sizing mechanism 11 includes a pair ofbelt-forwarding units 13.

Each belt-forwarding unit 13 includes a driving pulley 14, a pluralityof idler pulleys 15 and a non-end belt 16 (i.e. a belt 16 having noend). The driving pulley 14 is rotated by a motor which is a drivingsource received in the body 10. The idler pulleys 15 are rotatablysupported by the body 10. The non-end belt 16 is a circle-shaped beltand hung over the driving pulley 14 and the idler pulleys 15. Thenon-end belt 16 rotates around the driving pulley 14 and the idlerpulleys 15.

The pair of the belt-forwarding units 13 is arranged in the verticaldirection. The pair of the belt-forwarding units 13 puts the wire 1therebetween and allows the pulleys 14 to rotate reversely to each othersynchronously with the same number of revolution, so that the non-endbelt 16 is rotated to forward the wire 1 by a specific length thereof.

At this time, the pair of the belt-forwarding units 13 moves the wire 1along an arrow K shown in FIG. 1, which is parallel to the longitudinaldirection of the wire 1. That is, the pair of the belt-forwarding units13 moves the wire 1 along the longitudinal direction of the wire 1.

The cutting mechanism 12 is disposed on the downstream side of thebelt-forwarding units 13 along the arrow K. The cutting mechanism 12includes a pair of cutting blades 17, 18. The pair of cutting blades 17,18 is arranged in the vertical direction. That is, the pair of cuttingblades 17, 18 approaches toward or leaves away from each other in thevertical direction. When the pair of cutting blades 17, 18 approachestoward each other, the pair of cutting blades 17, 18 puts the wire 1,which is forwarded by the pair of the belt-forwarding units 13,therebetween and cuts the wire 1. When the pair of cutting blades 17, 18leaves away from each other, each blade 17, 18 leaves away from the wire1.

In the electric wire-cutting device 2, the pair of the belt-forwardingunits 13 puts the wire 1 therebetween in a state that the pair ofcutting blades 17, 18 of the cutting mechanism 12 is parted away fromeach other, so that the wire 1 is forwarded along the arrow K. After thewire 1 of a specific length thereof is forwarded, the driving pulleys 14of the belt-forwarding units 13 are halted. Then, the pair of cuttingblades 17, 18 approaches toward each other, puts the wire 1 therebetweenand cuts the wire 1. Thus, the electric wire-cutting device 2 moves thewire 1 along the arrow K.

In the coating device 3, the marks 23 are formed on the outer surface 5a of the wire 1, thereafter the coating layer 6 is formed on the marks23 and on the outer surface 5 a. As shown in FIG. 2, the coating device3 includes a coloring agent-spouting unit 31 as coloring agent-spoutingmeans, a spouting unit 32 as spouting means, an encoder 33 as detectingmeans, and a control device 34. The coloring agent-spouting unit 31 andthe spouting unit 32 are arranged along the arrow K.

As shown in FIG. 1, the coloring agent-spouting unit 31 is disposedbetween the belt-forwarding units 13 and the pair of cutting blades 17,18. As shown in FIG. 2, the coloring agent-spouting unit 31 includes anozzle 35 and a valve 36. The nozzle 35 faces the wire 1, which is movedalong the arrow K by the belt-forwarding units 13. A coloring agent CH(shown in FIG. 4) is supplied into the nozzle 35 from a coloringagent-supplying source 37 (shown in FIG. 2). The coloring agent CH hasthe color B as described above.

The valve 36 is linked to the nozzle 35. The valve 36 is also linked toa pressurized gas-supplying source 38 (shown in FIG. 2). The pressurizedgas-supplying source 38 supplies pressurized gas to the nozzle 35 by wayof the valve 36. Further, the pressurized gas-supplying source 38supplies pressurized gas to a nozzle 39 (explained later on) by way of avalve 40 (explained later on). When the valve 36 is opened, thepressurized gas supplied from the pressurized gas-supplying source 38causes the coloring agent CH in the nozzle 35 to spout out from thenozzle 35 toward the outer surface 5 a of the wire 1.

When the valve 36 is closed, the spouting of the coloring agent CH fromthe nozzle 35 is halted. As shown in FIG. 4, in the coloringagent-spouting unit 31, the valve 36 is opened for a predeterminedperiod of time in response to a signal transmitted from a CPU 47(explained later on) of the control device 34, so that a specific amountof the coloring agent CH is spouted toward the outer surface 5 a of thewire 1.

The coloring agent CH is a liquid substance, in which a coloringmaterial (organic substance for use in industry) is dissolved anddispersed in a solvent except water. The organic substance describedabove is a dye or a pigment (most of them being organic substances andsynthetic substances). Sometimes, a dye is used as a pigment and apigment is used as a dye. As an example, the coloring agent may be acoloring liquid or coating material. The coloring liquid is a liquid, inwhich a dye is dissolved or dispersed in a solvent. The coating materialis a material, in which a pigment is dispersed in a liquid dispersion.

When the outer surface 5 a of the wire 1 is colored with a coloringliquid, the dye permeates into the coating 5. When the outer surface 5 aof the wire 1 is colored with a coating material, the pigment adheres tothe outer surface 5 a without permeating into the coating 5. The dye ofthe coloring liquid and the pigment of the coating material areoil-soluble. That is, the dye of the coloring liquid does not dissolveor disperse in water. The pigment of the coating material does notdissolve in water.

That is, the coloring agent-spouting unit 31 dyes a part of the outersurface 5 a of the wire 1 with a dye or coats a part of the outersurface 5 a of the wire 1 with a pigment. That is, to mark the outersurface 5 a of the wire 1 (i.e. to form the marks 23) means to dye apart of the outer surface 5 a of the wire 1 with a dye or to coat a partof the outer surface 5 a of the wire 1 with a pigment.

Preferably, the solvent and liquid dispersion have an affinity to thesynthetic resin that constitutes the coating 5 in order to allow the dyeto securely permeate into the coating 5 or to allow the pigment tosecurely adhere to the outer surface 5 a.

As shown in FIG. 1, the spouting unit 32 is disposed between thebelt-forwarding units 13 and the pair of cutting blades 17, 18 andsituated further from the belt-forwarding units 13 than the coloringagent-spouting unit 31 is situated. That is, the coloring agent-spoutingunit 31 is disposed on the upstream side of the spouting unit 32 alongthe moving direction of the wire 1.

As shown in FIG. 2, the spouting unit 32 includes a nozzle 39 and avalve 40. The nozzle 39 faces the wire 1, which is forwarded along thearrow K by the belt-forwarding units 13. A coating liquid C (shown inFIG. 4) is supplied into the nozzle 39 from a coating liquid-supplyingsource 41 (shown in FIG. 2). The coating liquid C is transparent.

The valve 40 is linked to the nozzle 39. The valve 40 is also linked tothe pressurized gas-supplying source 38. When the valve 40 is opened,the pressurized gas supplied from the pressurized gas-supplying source38 causes the coating liquid C in the nozzle 39 to spout out from thenozzle 39 toward the outer surface 5 a of the wire 1. When the valve 40is closed, the spouting of the coating liquid C from the nozzle 39 ishalted. As shown in FIG. 4, in the spouting unit 32, the valve 40 isopened for a predetermined period of time in response to a signaltransmitted from the CPU 47 of the control device 34, so that a specificamount of the coating liquid C is spouted toward the outer surface 5 aof the wire 1.

The coating liquid C consists of a coating agent and solvent fordissolving the coating agent. The coating liquid C is in sol-form orgel-form. The coating agent consists of PVA, which constitutes thecoating layer 6.

Water, acetone or 2-propyl alcohol can be used as the solvent fordissolving the coating agent. The solvent for dissolving the coatingagent can be selected appropriately according to PVA, which is used asthe coating agent.

As shown in FIG. 2, the encoder 33 includes a rotor 42. The rotor 42 isrotatable around an axis. An outer peripheral surface of the rotor 42comes in contact with the outer surface 5 a of the wire 1, which is putbetween the pair of the belt-forwarding units 13. When the wire 1 isforwarded along the arrow K, the rotor 42 rotates. The forwardeddistance of the wire 1 along the arrow K is proportional to the numberof revolution of the rotor 42.

The encoder 33 is linked to the control device 34. When the rotor 42rotates per a specific angle, the encoder 33 outputs a pulse-shapedsignal to the control device 34. That is, the encoder 33 outputsinformation to the control device 34 in response to the moving speed ofthe wire 1 along the arrow K.

Thus, the encoder 33 measures information in response to the movingspeed of the wire 1 and outputs the information to the control device34. Normally, encoder 33 outputs pulse signal in response to theforwarded distance of the wire 1 with friction between the wire 1 andthe rotor 42 (i.e. roll attached to the encoder). However, in the eventthat the forwarded distance of the wire 1 does not coincide with thenumber of the pulse due to a condition of the outer surface 5 a of thewire 1, the speed information may be obtained at a different position ina different manner.

As shown in FIG. 3, the control device 34 includes a box-shaped devicebody 43 (shown in FIG. 1), memory 44 as storing means, known ROM(Read-only Memory) 45, RAM (Random Access Memory) 46, CPU (CentralProcessing Unit) 47, a plurality of valve-driving circuits 48, and aplurality of interfaces (indicating as I/F in FIG. 3; hereinafter I/F)49 as connectors. The control device 34 is a computer.

The control device 34 is linked to the encoder 33 and valves 36, 40 ofthe respective spouting units 31, 32 so as to control the whole of thecoating device 3. The device body 43 receives the memory 44, ROM 45, RAM46 and CPU 47. The memory 44 stores a pattern of the marks 23 to beformed on the outer surface 5 a of the wire 1.

Concretely, the memory 44 stores: a position at which the mark 23located most downstream along the arrow K is formed among the marks 23to be formed on the outer surface 5 a of the wire 1; the number of themarks 23; the distance D between the centers of the two marks adjacentto each other; a degree of opening of the valve 36 required for formingone mark 23; and a time period for which the valve 36 is kept open.

The memory 44 further stores: a degree of opening of the valve 40required for allowing the nozzle 39 to spout the coating liquid C withan amount which enables to coat the marks 23 with giving a desiredthickness of the mark 23; a time period for which the valve 40 is keptopen; and a distance L between the nozzle 35 and the nozzle 39.

The distance L also correspond to a distance between the spouting units31 and 32, that is, a distance between the coloring agent-spouting meansand the spouting means. The memory 44 may consist of a known nonvolatilestorage such as an EEPROM. The ROM 45 stores an action program of theCPU 47. The RAM 46 temporarily holds data, which are necessary uponcomputation of the CPU 47.

The CPU is the control means. The CPU receives information of the movingspeed of the wire 1 from the encoder 33. The CPU 47 also receives thepattern of the marks 23 from the memory 33. The CPU 47 also receives thedistance L, the degree of opening of the valve 40 as described above,and a time period for which the valve 40 is kept open. The CPU 47 opensthe valve 36 in a timing, at which the mark 23 situated at the mostdownstream along the arrow K is formed at a specific position, on thebasis of the moving speed of the wire 1, which is inputted from theencoder 33.

The CPU 47 opens or closes the valve 36 so that the distance between thecenters of the marks 23 formed on the outer surface 5 a of the wire 1becomes to the distance D described above in response to the movingspeed of the wire 1, which is inputted from the encoder 33. Further, theCPU 47 opens the valve 36 for the time period stored by the memory 44with the degree of opening stored by the memory 44, which allows a sizeof the mark 23 to be formed on the outer surface 5 a of the wire 1 tobecome a predetermined size. Thus, the CPU 47 allows the coloringagent-spouting unit 31 to spout the coloring agent CH toward the outersurface 5 a of the wire 1 so as to form the marks 23.

The CPU 47 judges whether or not the wire 1 moves by the distance Lafter the valve 36 is once opened in response to the moving speed of thewire 1, which is inputted from the encoder 33. When the CPU 47 judgesthat the wire 1 moves by the distance L after the valve 36 is onceopened, the CPU 47 opens the valve 40 with the degree of opening storedby the memory 44, which allows the coating layer 6 coats the marks 23with giving a desired thickness T of the coating layer 6.

Further, after the CPU 47 opens the valve 40 for the time period storedby the memory 44, the CPU 47 closes the valve 40. Thus, the CPU 47controls the spouting unit 32 so that the coating liquid C coats themarks 23, that is, the coating liquid C coats the coloring agent thatadheres to the outer surface 5 a of the wire 1. The CPU 47 allows thespouting unit 32 to spout the coating liquid C toward the coloring agentthat adheres to the outer surface 5 a of the wire 1.

The valve-driving circuits 48 and the I/F 49 are provided as many as thespouting units 31, 32, to which the valve-driving circuits 48 and theI/F 49 correspond. The valve-driving circuits 48 are linked to the CPU47. The valve-driving circuits 48 are linked to the respective valves36, 40 of the corresponding spouting units 31, 32 by way of the I/F 49.

When the valve-driving circuit 48 receives a signal for opening thecorresponding valve 36 or 40 from the CPU 47, the valve-driving circuit48 outputs the signal to the valve 36 or 40 by way of the I/F 49,thereby opening the valve 36 or 40.

Thus, the I/F 49 is used to electrically connect the valve-drivingcircuit 48 to the corresponding valve 36 or 40. The I/F is attached onan outer wall of the device body 43 or the like.

After the coating device 3 forms the marks 23 on the outer surface 5 aof the wire 1, when the coating layer 6 is formed on the marks 23, thepair of the belt-forwarding units 13 of the electric wire-cutting device2 forwards the wire 1 along the arrow K. When the CPU 47 receives apulse-shaped signal of a specific order from the encoder 33, first, theCPU allows the valve 36 to open and close six times according to thedistance D with the degree of opening stored in the memory 44 for thetime period stored in the memory 44.

Then, as shown in FIG. 4, the coloring agent-spouting unit 31 spouts thecoloring agent CH toward the outer surface 5 a of the wire 1 with aspecific amount thereof at a time. When the coloring agent CH adheres tothe outer surface 5 a of the wire 1, the solvent or the liquiddispersion thereof evaporates, so that the dye permeates or the pigmentadheres to the outer surface 5 a of the wire 1.

After the valve 36 of the coloring agent-spouting unit 31 once opens,when the CPU 47 judges that the wire 1 moves by the distance L on thebasis of the moving speed of the wire 1 transmitted from the encoder 33,CPU allows the valve 36 to open and close according to the distance Dwith the degree of opening stored in the memory 44 for the time periodstored in the memory 44.

Then, as shown in FIG. 4, the spouting unit 32 spouts the coating liquidC toward the marks 23 adhering to the outer surface 5 a of the wire 1,that is, toward the coloring agent CH with a specific amount thereof ata time. After the valve 36 of the coloring agent-spouting unit 31 onceopens, when the wire 1 moves by the distance L, the CPU 47 allows thevalve 40 of the spouting unit 32 to open or close. The coating liquid Cthat adheres to the outer surface 5 a of the wire 1 coats the marks 23with the coating agent after the solvent thereof evaporates. Thus, thecoating layer 6 is formed on the marks 23 and on the outer surface 5 aof the wire 1.

Then, after the pair of the belt-forwarding units 13 of the electricwire-cutting device 2 forwards the wire 1 by a specific length thereof,the pair of the belt-forwarding units 13 halts. The cutting blades 17,18 of the cutting mechanism 12 cuts the wire 1, in which the marks 23are formed on the outer surface 5 a of the wire 1, thereby obtaining thewire 1 shown in FIG. 5, in which the marks 23 are formed on the outersurface 5 a of the wire 1 and the marks 23 are coated with the coatinglayer 6.

In the preferred embodiment, the coating layer 6 is formed on the marks23 that are formed on the outer surface 5 a of the wire 1. The coatinglayer 6 consists of PVA. Since the dye of the coloring liquid or thepigment of the coating material as the coloring agent CH is oil-soluble,the coloring agent CH hardly passes through the coating layer 6consisting of water-soluble PVA (polyvinylalcohol).

Therefore, the coating layer 6 prevents the coloring agent CH, whichforms the marks 23, from coming off from the outer surface 5 a of theelectric wire 1. Particularly, in the electric wire 1 for use in a motorvehicle, since the coating layer 6 consists of water-soluble PVA,therefore the coloring agent CH is prevented from coming off from theouter surface 5 a of the electric wire 1 even if the wires 1 are used insevere circumstances for a long period of time.

The thickness T of the coating layer 6 consisting of PVA is from 0.02 mmto 0.22 mm. Therefore, the coating layer 6 securely prevents thecoloring agent CH, which forms the mark 23, from coming off from theouter surface 5 a of the electric wire 1. Particularly, in the electricwire 1 for use in a motor vehicle, since the coating layer 6 consists ofwater-soluble PVA and is formed to have the thickness described above,therefore the coloring agent CH is securely prevented from coming offfrom the outer surface 5 a of the electric wire 1 even if the wires 1are used in severe circumstances for a long period of time.

The spouting unit 32 spouts the coating liquid C toward the outersurface 5 a of the wire 1 with a specific amount thereof at a time.Therefore, the distance and the amount for spouting the coating liquid Ccan be adjusted according to the necessary thickness of the coatinglayer 6. Therefore, the coating liquid C can effectively adhere to theouter surface 5 a of the wire 1. Therefore, the coating layer 6 can beformed without wasting the coating liquid C.

The encoder 33 detects the moving speed of the wire 1. The CPU 47 allowsthe spouting unit 32 to spout the coating liquid C toward the coloringagent adhering on the outer surface 5 a of the wire 1 on the basis ofthe moving speed of the wire 1. Therefore, the coating layer 6 issecurely formed on the coloring agent adhering on the outer surface 5 aof the wire 1. Therefore, the coloring agent adhering on the outersurface 5 a of the electric wire 1 is securely prevented from coming offas time passing. Further, by forming the coating layer 6 on the coloringagent, the coating liquid C can effectively adhere to the outer surface5 a of the wire 1. Therefore, the coating layer 6 can be formed withoutwasting the coating liquid C.

The coating device 3 is mounted on the electric wire-cutting device 2.Therefore, when the long wire 1 is cut into a specific length, thecoating layer 6 can be formed on the outer surface 5 a of the wire 1,thereby reducing a space for placing devices and man-hour for processingthe wire 1.

In the preferred embodiment described above, the coating layer 6consists of PVA. However, instead, the coating layer 6 may consist ofethylene-vinylalcohol copolymer (i.e. EVA copolymer). In this case, thecoating agent constituting the coating liquid C consists of EVAcopolymer, which constitutes the coating layer 6. The solvent fordissolving the coating agent may be toluene, xylene or hexane. Thesolvent for dissolving the coating agent can be appropriately selectedaccording to the EVA copolymer used as the coating agent.

The solvent described above is heated and the EVA copolymer is dissolvedin the heated solvent, thereby obtaining the coating liquid C. Aconcentration of the coating liquid C received in the coatingliquid-supplying source 41 is set to be a concentration so that asolvent consisting of the EVA copolymer is not deposited whentemperature of the coating liquid is returned to an ordinarytemperature.

If the coating layer 6 consists of EVA copolymer, a thickness of thecoating layer 6 is from 0.03 mm to 0.175 mm.

The coating layer 6 is formed on the marks 23 that are formed on theouter surface 5 a of the wire 1. The coating layer 6 consists of EVAcopolymer. Since the dye of the coloring liquid or the pigment of thecoating material as the coloring agent CH is oil-soluble, the coloringagent CH hardly passes through the coating layer 6 consisting ofwater-soluble EVA copolymer. Therefore, the coating layer 6 prevents thecoloring agent CH, which forms the marks 23, from coming off from theouter surface 5 a of the electric wire 1. Particularly, in the electricwire 1 for use in a motor vehicle, since the coating layer 6 consists ofwater-soluble EVA copolymer, therefore the coloring agent CH isprevented from coming off from the outer surface 5 a of the electricwire 1 even if the wires 1 are used in severe circumstances for a longperiod of time.

The thickness T of the coating layer 6 consisting of EVA copolymer isfrom 0.03 mm to 0.175 mm. Therefore, the coating layer 6 securelyprevents the coloring agent CH, which forms the mark 23, from coming offfrom the outer surface 5 a of the electric wire 1. Particularly, in theelectric wire 1 for use in a motor vehicle, since the coating layer 6consists of water-soluble EVA copolymer and is formed to have thethickness described above, therefore the coloring agent CH is securelyprevented from coming off from the outer surface 5 a of the electricwire 1 even if the wires 1 are used in severe circumstances for a longperiod of time.

A degree of color-coming-off of the coloring agent was measured when thecoating layer 6 is formed with various materials. The result is shown inTable 1. TABLE 1 Color Difference when thickness of coating layer is 0.1mm Evaluation Example A 2 good Example B 10 good Comparative Example A43 no good Comparative Example B 38 no good Comparative Example C 48 nogood Comparative Example D 53 no good Comparative Example E 49 no goodComparative Example F 66 no good Comparative Example G 84 no good

In the measurement, coating liquids C consisting of various materialswere spouted with a specific amount thereof at a time toward an outersurface of a sheet material 100 a (shown in FIGS. 10A and 10B), whichconsists of the same material as that of the coating 5 of the wire 1 andthe outer surface of which is colored similarly to the wire 1, from thespouting unit 32 of the coating device 3. Thereby, the coating layer 6was formed on a surface of the sheet material 100 a.

When the coating layers 6 consisting of the various respective materialswere formed, the degrees of coming-off of the coloring agent CH from theouter surface were measured. The thickness T of the coating layer 6 wasset to be 0.1 mm. In the measurement, as shown in FIG. 10A, the sheetmaterial 100 a was piled together with a sheet material 100 c, whichconsisted of the same material as that of the coating 5 of the wire 1and not colored and on which the coating layer 6 was not formed. Thesesheet materials 100 a and 100 c were put between a pair of members 101consisting of glass or the like. Then, a pressure P (for example 140kgf/cm²) was applied thereon in a direction in which the sheet materials100 a and 100 c approach toward each other.

Then, on the condition that the pressure P was applied, the sample wasleft in a room that was heated at 80° C. for 24 hours. Thereafter, acolor of the outer surface of the sheet material 100 c and a color ofthe outer surface of the sheet material 100 b, which was not coloredsimilarly to the sheet material 100 c, were compared with each other.Thereby, the degree of color transferred from the sheet material 100 ato the sheet material 100 c was measured. Here, the sheet material 100 bwas a sheet material, which consisted of the same material as that ofthe coating 5 of the wire 1 and was not colored similarly to the sheetmaterial 100 c and on which the coating layer 6 was not formed. Thesheet material 100 b was neither subjected to the pressurization norheating as described above.

The color difference (ΔE) shown in Table 1 indicates the degree of thecoloring agent transferred from under the coating layer 6 of the sheetmaterial 100 a, which was subjected to the condition shown in FIG. 10Afor 24 hours, to the sheet material 100 c in comparison with the sheetmaterial 100 b (shown in FIG. 10B) as a standard. That is, the colordifference (ΔE) indicates the degree of coming-off of the coloring agent(hereinafter, color-coming-off) existed under the coating layer 6 of thesheet material 100 a, which was subjected to the condition shown in FIG.10A for 24 hours, from the outer surface.

Table 1 reveals that if the color difference (ΔE) increases, that is, ifthe color-coming-off increases, the coloring agent comes off from theouter surface, causing a decrease in the effect of the coating layer 6.In other words, if the color difference (ΔE) decreases, that is, if thecolor-coming-off decreases, the coloring agent hardly comes off from theouter surface, causing an increase in the effect of the coating layer 6.

In Table 1, in Comparative Example A, the coating layer 6 consisted ofpolyolefin. In Comparative Example B, the coating layer 6 consisted ofurethan. In Comparative Example C, the coating layer 6 consisted ofsilicone resin. In Comparative Example D, the coating layer 6 consistedof acrylic resin. In Comparative Example E, the coating layer 6consisted of natural rubber. In Comparative Example F, the coating layer6 consisted of fluorine resin. In Comparative Example G, the coatinglayer 6 consisted of lacquer. That is, in these Comparative ExamplesA-G, each coating layer 6 was oil-soluble, which was not water-soluble.

In Table 1, in Example A, the coating layer 6 consisted ofpolyvinylalcohol (PVA). In Example B, the coating layer 6 consisted ofethylene-vinylalcohol copolymer (EVA copolymer).

If the color difference (ΔE) exceeds 68, it means that thecolor-coming-off is larger than that of a sheet material having nocoating layer 6 formed thereon. That is, if the color difference (ΔE)exceeds 68, it means that there is no effect of the coating layer 6.

If the color difference (ΔE) is less than 20, it means that the coloringagent hardly comes off. Further, if the color difference (ΔE) is lessthan 10, it means that the coloring agent never comes off.

Table 1 reveals that in Comparative Example G the color difference (ΔE)exceeded 68, indicating that there was no effect of the coating layer 6.Further, Table 1 reveals that in the Comparative Examples A-F the colordifference (ΔE) exceeded 20, indicating that the effect of the coatinglayer 6 was not sufficient, that is, the coating layer could not preventthe color-coming-off of the coloring agent from occurring. On the otherhand, in the Examples A and B the color difference (ΔE) was not morethan 10, indicating that the coating layer could prevent thecolor-coming-off of the coloring agent from occurring.

According to the result shown in Table 1, if the coating layer 6consists of PVA or EVA, the coloring agent CH hardly passes through thecoating layer 6. That is, in such a case, the coating layer 6 canprevent the coloring agent that constitutes the mark 23 from coming offfrom the outer surface 5 a of the wire 1, that is, the coating layer 6can prevent the color-coming-off from occurring. Particularly, in theelectric wire 1 for use in a motor vehicle, since the coating layer 6consists of water-soluble PVA or EVA copolymer, therefore the coloringagent is prevented from coming off from the outer surface 5 a of theelectric wire 1 even if the wires 1 are used in severe circumstances fora long period of time.

Further, the degree of color-coming-off of the coloring agent wasmeasured when the thickness T of the coating layer consisting of PVA orEVA copolymer was changed. The result is shown in FIG. 9. Themeasurement, the result of which being shown in FIG. 9, was carried outon the same condition as that of the measurement, the result of whichbeing shown in Table 1.

In Comparative Example H shown in FIG. 9, the coating layer 6 was notformed. In Example A shown in FIG. 9, the coating layer consisted ofPVA. In Example B shown in FIG. 9, the coating layer consisted of EVAcopolymer.

According to the result shown in FIG. 9, for both of Examples A and B,when the thickness T of the coating layer 6 was increased, the coloringagent hardly came off. In Example A, when the thickness T was from 0.02mm to 0.22 mm, the color difference (ΔE) was not more than 20. Further,when the thickness T was from 0.023 mm to 0.22 mm, the color difference(ΔE) was not more than 10.

That is, in Example A, if the thickness T of the coating layer 6 wasfrom 0.02 mm to 0.22 mm, the color-coming-off of the coloring agenthardly occurred. Further, in Example A, if the thickness T of thecoating layer 6 was from 0.023 mm to 0.22 mm, the color-coming-off ofthe coloring agent never occurred.

In Example B, when the thickness T was from 0.03 mm to 0.175 mm, thecolor difference (ΔE) was not more than 20. Further, when the thicknessT was from 0.1 mm to 0.175 mm, the color difference (ΔE) was not morethan 10.

That is, in Example B, if the thickness T of the coating layer 6 wasfrom 0.03 mm to 0.175 mm, the color-coming-off of the coloring agenthardly occurred. Further, in Example B, if the thickness T of thecoating layer 6 was from 0.1 mm to 0.175 mm, the color-coming-off of thecoloring agent never occurred.

In the preferred embodiment described above, the coating layer 6consisting of PVA is set to have the thickness T from 0.02 mm to 0.22mm. However, the thickness T of the coating layer 6 consisting of PVAmay be set from 0.023 mm to 0.22 mm.

In the latter case, as shown in FIG. 9, the color difference (ΔE) is notmore than 10. That is, the coloring agent CH very hardly passes throughthe coating layer 6. That is, the coating layer 6 can more securelyprevent the coloring agent CH that constitutes the mark 23 from comingoff from the outer surface 5 a of the wire 1, that is, the coating layer6 can more securely prevent the color-coming-off of the coloring agentCH from occurring. Particularly, in the electric wire 1 for use in amotor vehicle, since the coating layer 6 consists of water-soluble PVAand is formed to have the thickness T as described above, therefore thecoloring agent CH is more securely prevented from coming off from theouter surface 5 a of the electric wire 1 even if the wires 1 are used insevere circumstances for a long period of time.

Further, in the preferred embodiment described above, the coating layer6 consisting of EVA copolymer is set to have the thickness T from 0.03mm to 0.175 mm. However, the thickness T of the coating layer 6consisting of EVA copolymer may be set from 0.1 mm to 0.175 mm.

In the latter case, as shown in FIG. 9, the color difference (ΔE) is notmore than 10. That is, the coloring agent CH very hardly passes throughthe coating layer 6. That is, the coating layer 6 can more securelyprevent the coloring agent CH that constitutes the mark 23 from comingoff from the outer surface 5 a of the wire 1, that is, the coating layer6 can more securely prevent the color-coming-off of the coloring agentCH from occurring. Particularly, in the electric wire 1 for use in amotor vehicle, since the coating layer 6 consists of water-soluble EVAcopolymer and is formed to have the thickness T as described above,therefore the coloring agent CH is more securely prevented from comingoff from the outer surface 5 a of the electric wire 1 even if the wires1 are used in severe circumstances for a long period of time.

In the preferred embodiment described above, only one coloringagent-spouting unit 31 is provided. However, instead, a plurality of thecoloring agent-spouting units 31 may be provided so that the marks 23are formed with a plurality of the coloring agents, that is, with aplurality of colors.

In the preferred embodiment described above, the control device 34 isconstituted by a computer including the ROM 45, RAM 46, CPU 47 and soon. However, instead, the control device 34 may be constituted by aknown digital circuit and so on. In the latter case, a circuit forcounting the pulse-shaped signals transmitted from the encoder 33 and acircuit for judging that the valves 36, 40 be opened or closed when thepulse-shaped signal of which turn is inputted are preferably used.

In the preferred embodiment described above, the wires 1 that constitutea wiring harness to be mounted on a motor vehicle are described.However, the wires 1 can be used for various electronic instruments orelectrical machines such as a portable computer besides the motorvehicle.

Further, in the present invention, as the coloring liquid or coatingmaterial, various material may be used, such as acrylic coatingmaterial, ink (dye or pigment) and UV-ink.

INDUSTRIAL APPLICABILITY

In the electric wire of the present invention as defined in claim 1, thecoating layer is formed on the mark formed on the outer surface of theelectric wire. The coating layer consists of polyvinylalcohol. Since thedye of the coloring liquid and the pigment of the coating material asthe coloring agent are oil-soluble, the coloring agent hardly passesthrough the coating layer consisting of water-soluble polyvinylalcohol.Therefore, the coating layer prevents the coloring agent, which formsthe mark, from coming off from the outer surface of the electric wire.Particularly, in the electric wire for use in a motor vehicle, since thecoating layer consists of water-soluble polyvinylalcohol, therefore thecoloring agent is prevented from coming off from the outer surface ofthe electric wire even if the wires are used in severe circumstances fora long period of time.

In the electric wire of the present invention as defined in claim 2, athickness of the coating layer is from 0.02 mm to 0.22 mm. Therefore,the coating layer securely prevents the coloring agent, which forms themark, from coming off from the outer surface of the electric wire.Particularly, in the electric wire for use in a motor vehicle, since thecoating layer consists of water-soluble polyvinylalcohol and is formedto have the thickness described above, therefore the coloring agent issecurely prevented from coming off from the outer surface of theelectric wire even if the wires are used in severe circumstances for along period of time.

In the electric wire of the present invention as defined in claim 3, athickness of the coating layer is from 0.023 mm to 0.22 mm. Therefore,the coating layer more securely prevents the coloring agent, which formsthe mark, from coming off from the outer surface of the electric wire.Particularly, in the electric wire for use in a motor vehicle, since thecoating layer consists of water-soluble polyvinylalcohol and is formedto have the thickness described above, therefore the coloring agent ismore securely prevented from coming off from the outer surface of theelectric wire even if the wires are used in severe circumstances for along period of time.

In the electric wire of the present invention as defined in claim 4, thecoating layer is formed on the mark formed on the outer surface of theelectric wire. The coating layer consists of ethylene-vinylalcoholcopolymer. Since the dye of the coloring liquid and the pigment of thecoating material are oil-soluble, the coloring agent hardly passesthrough the coating layer consisting of water-solubleethylene-vinylalcohol copolymer. Therefore, the coating layer preventsthe coloring agent, which forms the mark, from coming off from the outersurface of the electric wire. Particularly, in the electric wire for usein a motor vehicle, since the coating layer consists of water-solubleethylene-vinylalcohol copolymer, therefore the coloring agent isprevented from coming off from the outer surface of the electric wireeven if the wires are used in severe circumstances for a long period oftime.

In the electric wire of the present invention as defined in claim 5, athickness of the coating layer is from 0.03 mm to 0.175 mm. Therefore,the coating layer securely prevents the coloring agent, which forms themark, from coming off from the outer surface of the electric wire.Particularly, in the electric wire for use in a motor vehicle, since thecoating layer consists of water-soluble ethylene-vinylalcohol copolymerand is formed to have the thickness described above, therefore thecoloring agent is securely prevented from coming off from the outersurface of the electric wire even if the wires are used in severecircumstances for a long period of time.

In the electric wire of the present invention as defined in claim 6, athickness of the coating layer is from 0.1 mm to 0.175 mm. Therefore,the coating layer more securely prevents the coloring agent, which formsthe mark, from coming off from the outer surface of the electric wire.Particularly, in the electric wire for use in a motor vehicle, since thecoating layer consists of water-soluble ethylene-vinylalcohol copolymerand is formed to have the thickness described above, therefore thecoloring agent is more securely prevented from coming off from the outersurface of the electric wire even if the wires are used in severecircumstances for a long period of time.

1. An electric wire comprising: an electrically conductive core wire; acoating consisting of synthetic resin for coating the core wire; a markformed on a part of an outer surface of the coating by allowing acoloring agent to adhere to the part; and a coating layer formed on themark and the outer surface of the coating, the coating layer coating themark, wherein the coating layer consists of polyvinylalcohol.
 2. Theelectric wire according to claim 1, wherein a thickness of the coatinglayer is from 0.02 mm to 0.22 mm.
 3. The electric wire according toclaim 1, wherein a thickness of the coating layer is from 0.023 mm to0.22 mm.
 4. An electric wire comprising: an electrically conductive corewire; a coating consisting of synthetic resin for coating the core wire;a mark formed on a part of an outer surface of the coating by allowing acoloring agent to adhere to the part; and a coating layer formed on themark and the outer surface of the coating, the coating layer coating themark, wherein the coating layer consists of ethylene-vinylalcoholcopolymer.
 5. The electric wire according to claim 4, wherein athickness of the coating layer is from 0.03 mm to 0.175 mm.
 6. Theelectric wire according to claim 4, wherein a thickness of the coatinglayer is from 0.1 mm to 0.175 mm.